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/*
* SMP support for ppc.
*
* Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
* deal of code from the sparc and intel versions.
*
* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
*
* PowerPC-64 Support added by Dave Engebretsen, Peter Bergner, and
* Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#undef DEBUG
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/cache.h>
#include <linux/err.h>
#include <linux/sysdev.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
#include <asm/ptrace.h>
#include <asm/atomic.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/paca.h>
#include <asm/time.h>
#include <asm/machdep.h>
#include <asm/cputable.h>
#include <asm/system.h>
#include <asm/abs_addr.h>
#include "mpic.h"
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif
cpumask_t cpu_possible_map = CPU_MASK_NONE;
cpumask_t cpu_online_map = CPU_MASK_NONE;
cpumask_t cpu_sibling_map[NR_CPUS] = { [0 ... NR_CPUS-1] = CPU_MASK_NONE };
EXPORT_SYMBOL(cpu_online_map);
EXPORT_SYMBOL(cpu_possible_map);
struct smp_ops_t *smp_ops;
static volatile unsigned int cpu_callin_map[NR_CPUS];
extern unsigned char stab_array[];
void smp_call_function_interrupt(void);
int smt_enabled_at_boot = 1;
#ifdef CONFIG_PPC_MULTIPLATFORM
void smp_mpic_message_pass(int target, int msg)
{
/* make sure we're sending something that translates to an IPI */
if ( msg > 0x3 ){
printk("SMP %d: smp_message_pass: unknown msg %d\n",
smp_processor_id(), msg);
return;
}
switch ( target )
{
case MSG_ALL:
mpic_send_ipi(msg, 0xffffffff);
break;
case MSG_ALL_BUT_SELF:
mpic_send_ipi(msg, 0xffffffff & ~(1 << smp_processor_id()));
break;
default:
mpic_send_ipi(msg, 1 << target);
break;
}
}
int __init smp_mpic_probe(void)
{
int nr_cpus;
DBG("smp_mpic_probe()...\n");
nr_cpus = cpus_weight(cpu_possible_map);
DBG("nr_cpus: %d\n", nr_cpus);
if (nr_cpus > 1)
mpic_request_ipis();
return nr_cpus;
}
void __devinit smp_mpic_setup_cpu(int cpu)
{
mpic_setup_this_cpu();
}
void __devinit smp_generic_kick_cpu(int nr)
{
BUG_ON(nr < 0 || nr >= NR_CPUS);
/*
* The processor is currently spinning, waiting for the
* cpu_start field to become non-zero After we set cpu_start,
* the processor will continue on to secondary_start
*/
paca[nr].cpu_start = 1;
mb();
}
#endif /* CONFIG_PPC_MULTIPLATFORM */
static void __init smp_space_timers(unsigned int max_cpus)
{
int i;
unsigned long offset = tb_ticks_per_jiffy / max_cpus;
unsigned long previous_tb = paca[boot_cpuid].next_jiffy_update_tb;
for_each_cpu(i) {
if (i != boot_cpuid) {
paca[i].next_jiffy_update_tb =
previous_tb + offset;
previous_tb = paca[i].next_jiffy_update_tb;
}
}
}
void smp_message_recv(int msg, struct pt_regs *regs)
{
switch(msg) {
case PPC_MSG_CALL_FUNCTION:
smp_call_function_interrupt();
break;
case PPC_MSG_RESCHEDULE:
/* XXX Do we have to do this? */
set_need_resched();
break;
#if 0
case PPC_MSG_MIGRATE_TASK:
/* spare */
break;
#endif
#ifdef CONFIG_DEBUGGER
case PPC_MSG_DEBUGGER_BREAK:
debugger_ipi(regs);
break;
#endif
default:
printk("SMP %d: smp_message_recv(): unknown msg %d\n",
smp_processor_id(), msg);
break;
}
}
void smp_send_reschedule(int cpu)
{
smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE);
}
#ifdef CONFIG_DEBUGGER
void smp_send_debugger_break(int cpu)
{
smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
}
#endif
static void stop_this_cpu(void *dummy)
{
local_irq_disable();
while (1)
;
}
void smp_send_stop(void)
{
smp_call_function(stop_this_cpu, NULL, 1, 0);
}
/*
* Structure and data for smp_call_function(). This is designed to minimise
* static memory requirements. It also looks cleaner.
* Stolen from the i386 version.
*/
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock);
static struct call_data_struct {
void (*func) (void *info);
void *info;
atomic_t started;
atomic_t finished;
int wait;
} *call_data;
/* delay of at least 8 seconds on 1GHz cpu */
#define SMP_CALL_TIMEOUT (1UL << (30 + 3))
/*
* This function sends a 'generic call function' IPI to all other CPUs
* in the system.
*
* [SUMMARY] Run a function on all other CPUs.
* <func> The function to run. This must be fast and non-blocking.
* <info> An arbitrary pointer to pass to the function.
* <nonatomic> currently unused.
* <wait> If true, wait (atomically) until function has completed on other CPUs.
* [RETURNS] 0 on success, else a negative status code. Does not return until
* remote CPUs are nearly ready to execute <<func>> or are or have executed.
*
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler.
*/
int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
int wait)
{
struct call_data_struct data;
int ret = -1, cpus;
unsigned long timeout;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
data.func = func;
data.info = info;
atomic_set(&data.started, 0);
data.wait = wait;
if (wait)
atomic_set(&data.finished, 0);
spin_lock(&call_lock);
/* Must grab online cpu count with preempt disabled, otherwise
* it can change. */
cpus = num_online_cpus() - 1;
if (!cpus) {
ret = 0;
goto out;
}
call_data = &data;
wmb();
/* Send a message to all other CPUs and wait for them to respond */
smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_CALL_FUNCTION);
/* Wait for response */
timeout = SMP_CALL_TIMEOUT;
while (atomic_read(&data.started) != cpus) {
HMT_low();
if (--timeout == 0) {
printk("smp_call_function on cpu %d: other cpus not "
"responding (%d)\n", smp_processor_id(),
atomic_read(&data.started));
debugger(NULL);
goto out;
}
}
if (wait) {
timeout = SMP_CALL_TIMEOUT;
while (atomic_read(&data.finished) != cpus) {
HMT_low();
if (--timeout == 0) {
printk("smp_call_function on cpu %d: other "
"cpus not finishing (%d/%d)\n",
smp_processor_id(),
atomic_read(&data.finished),
atomic_read(&data.started));
debugger(NULL);
goto out;
}
}
}
ret = 0;
out:
call_data = NULL;
HMT_medium();
spin_unlock(&call_lock);
return ret;
}
EXPORT_SYMBOL(smp_call_function);
void smp_call_function_interrupt(void)
{
void (*func) (void *info);
void *info;
int wait;
/* ca
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